WOGE

Where on Google Earth #496

3 Comments

With WOGE 495, Ole showed us some interesting mines, fjords, and a shear zone on Senja island in Norway.

Here is WOGE 496. It may be a bit challenging, but I think there are a few clues in there.
woge_496

Post the latitude, longitude, and a description of the geology/hydrology/other-relevant-ology in the comments. An archive of the past locations and some tips for searching are available here.

Good luck!

3 thoughts on “Where on Google Earth #496”

  1. Business in South Germany is very demanding lately. Capacities are rare and everybody is working long hours. So do I, and therefore my WOGE activities are kind of slow recently.

    47.773, -90.423 Grand Marais, Cook County, Minnesota

    “Some of the oldest exposed rock on the planet underlies Lutsen-Tofte-Schroeder, Grand Marais, the Gunflint Trail and Grand Portage. Lake Superior rests in a formation of ancient Precambrian bedrock known as the Canadian Shield, which is over two billion years old.

    Two dramatic geological events shaped the Cook County landscape:

    A splitting-apart of the Earth’s crust, which caused a system of fissures called the Mid-continent Rift System. The splitting opened the earth’s core, enabling hot molten rock to well up, forming basalt flows that can be seen today along Lake Superior’s North Shore.
    Ice ages. Starting about 2 million years ago, glaciation and glacial recession carved the Great Lakes, the Boundary Waters Canoe Area Wilderness/BWCAW, and the ten thousand lakes for which Minnesota is known”. [http://www.visitcookcounty.com/things-to-do/geology/]

    Like

  2. That’s it!
    Here we are seeing (vegetation on top of) lava flows of the North Shore Volcanic Group, part of the Mid-Continent Rift system. The flows are dipping at about 20° SSE. One resistant flow makes up the breakwater of Grand Marais harbor, and a tombolo (rock wall formed by the longshore current) leads out to it.

    Further southwest along the shore is Good Harbor Bay. It is home to a spectacular roadcut, where a lava flow moved across the top of inter-flow sediments, possibly into a lake (evidence for lake interaction not pictured).

    Underlying the surface rocks of this area is the Duluth Complex; it may even have surface outcrops in the extreme northwestern portion of the image area.

    For a geologic map of Minnesota, I refer you here.

    Like

Comments are closed.